Radio receiving method and apparatus



Aug. 7, 11923.. 1,464,322

' F. A. KOLSTER RADIO RECEIVING METHOD AND APPARATUS Filed Nov. 26 1920INVEN TOR.

4 A TTORNEY.

Patented Aug. 7, 1923.

UNITED STATES PATENT OFFICE.

FREDERICK A. KOLSTER, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OFONE-THIRD T0 CORNELIUS D. EHRET, 0F PHILADELPHIA, PENNSYLVANIA.

RADIO RECEIVING METHOD AND APPARATUS.

Application filed November 26, 1920. Serial No. 426,504.

To all whom it may concern: Be it known that I, FREDERICK A. Kons'rnn, acitizen of the United States,.residing at Washington, District ofColumbia, have invented new and useful Radio Receiving Methods andApparatus, of which the following is a specification. My inventionrelates to a method of and apparatus for receiving signals representedin transmission by undamped elect'ro-radi- I ant energy waves.

In accordance with my invention, un-

damped signal waves are received and made audible in a telephonereceiver or the like by employment of a source of fluctuating oralternating current of audible frequency, the telephone being coupled tothe circuits of integrating, rectifying or equivalent detectors, thecouplings and circuit'arrangements being such that when no signal isbeing received there is no response by the telephone, and when a signalisfreceived', energy from the source of fluctuating or alternating.

current affects the telephone receiver to duce an audible response.

My invention resides in the method and apparatus hereinafter describedand claimed. For an illustration of some of the forms my invention maytake, reference is to be had to the accompanying drawing, in which:

Fig.1 is a diagrammatic view of receiv ing apparatus embodying myinvention and suitable for carrying out my method.

Fig. 2 is a diagrammatic view of a modification.

Referring to Fig. 1, R is a receiving an tenna or other absorbingstructure which, in the example illustrated, is connected to earth orcounter-capacity E through the tuning inductance L and the primary P ofan oscillation transformer whose secondary S is included in a circuittuned by the variable condenser C. It is preferred that the secondary S,particularly when the detector structure is of the thermionic or audiontype, shall have very high inductance so that the potentials of itsopposite ends at any inmionic devices A and A are related to theopposite ends of the inductance or secondary S. I

The audion A comprises the plate or anode a, the grid 9 and theelectron-emitting body or incandescent filament the latter traversed bycurrent from t e battery 6, the magnitude of the filament current beingadjustable by the variable resistance 0. The grid 9 is-connected throughthe grid condenser K with one terminal of the secondary S, a highresistance d connected to the grid g and filament 7 serving as a gridleak.

The parts of the audion A and associated connections are similar'tothose described connection with'device A. One terminal of the grid 9? isconnected through grid condenser K with the opposite terminal of thesecondary S, and there may be employed a grid leak d.

of a transformer whose secondary is 8 The secondaries s and s areconnected in series with each other and with the telephone receiver T'.

Common to the anode circuits of the audions is the secondary s of anaudio frequency transformer in circuit with wh se' primary p is anysuitable source S of fuctuating or alternating current of frequencyequal to or corresponding with the fr quency of the note which it isdesired shall be produced in the telephone T.

When. no signal is being received, the source S will cause impressionupon the circuit of the telephone T of a current which would produce aresponse thereby if it were not for the fact that the couplings p, s and0 8 produced, by suitable winding or mode of connection, equal andopposite effects upon the circuit of the telephone T. ccordingly, whenno signal is being received, the source S has no effect upon thetelephone T.

When, however, undamped signal waves are received, the circuit S C beingattuned thereto, as well as the antenna circuit, op

osite ends of the inductance or secondary g will attain widely differentpotentials, the potential of the grid g rising, for example, while thepotential of the grid g falls. The current in one anode circuittherefore greatly increases while the other greatly dimin-" ishes, and.accordingly the net effect of the couplings p, s and 71 s is no longerzero, and there is transferred to the circuit of the telephone T currentwhich causes its re-- sponse evidenced by the production of a soundwhose frequency is equal to or corresponds with the frequency of thecurrent delivered by the source S In Fig. 2 the arrangement issubstantially the same as that in Fig. 1, except that the anode circuitsof the audions A and A are separate and distinct, and the source S iscoupled to both anode circuits through the transformers 27, 25 In thiscase, however, the action is similar to that described in connectionwith Fig. 1 in that when no signal is being received there is noresponse by the telephone T, and when a signal is received, thetelephone T produces a note whose frequency is equal to or correspondswith the frequency of the current delivered by the source S As wellunderstood in the radio art, the received energy of radio frequency maybe amplified, as by a plurality of stages of radio frequency thermionicamplifiers,whose output circuit is coupled to the above mentionedinductance or secondary S. Similarly, the coupling secondaries s and s'may deliver to the input circuit of audio frequency amplifyingapparatus, as a plurality of stages of audio frequency thermionicamplifiers, in whose output circuit the telephone T may be connected.

W hat I claim is:

1. The method of rendering undamped waves of radio frequencyintelligible as signals of audio frequency independent of thefrequencyof said waves, which consists in subjecting detector input circuits tothe received energy, subjecting the output circuits to a source ofcurrent of audible frequency, and subjectin a. signal translatinginstrument to equal and opposite effects of said output circuits when nosignal is received and to a current when a signal is received, offrequency independent of the frequency of the received waves andcorresponding with the frequency of said source of current.

2. Apparatus for rendering undamped waves of radio frequencyintelligible as signals of audio frequency independent of the frequencyof said waves comprising a plurality of devices having input and outputcircuits, means for subjecting the input circuits to the receivedenergy, a signal translating instrument having equal and oppositecouplings to the output circuits when no signal is received, and asource of current of audiblefrequency associated with the outputcircuits. I

3. Apparatus for rendering undamped waves of radio frequencyintelligible as signals of audio frequency independent of the frequencyof said waves comprising a plurality of thermionic devices eachcomprising an anode, cathode and grid, means for changing the.potentials of said grids in opposite senses by received energy, a signaltranslating instrument, a coupling between the same and each of theanode circuits, and a source of current of audible frequency associatedwith the anode circuits, said couplings producing equal and oppositeeffects upon said signal translating instrument when no signal isreceived and effecting in the circuit of said signal translatinginstrument when a signal is received a current of frequency independentof the frequency of said waves and corresponding with the frequency ofsaid source.

4. Apparatus for rendering undamped waves of radio frequencyintelligible as signals of audio frequency independent of the frequencyof said Waves comprising a plurality of thermionic devices eachcomprising an anode, cathode and grid, means for changing the potentialsof said grids in opposite senses by received energy, a signaltranslating instrument, a coupling between the same and each of theanode circuits, and

a source of current of audible frequency associated with the anodecircuits, said couplings producing equal and opposite effects upon saidsignal translating instrument when no signal is received and effectingin the circuit of said signal translating instrument when a signal isreceived a current of frequency independent of the frequency of saidwaves and corresponding with the frequency of said source, said anodecircuits being in part in common.

5. Apparatus for rendering" undamped waves of radio frequencyintelligible as sig nals of audio frequency independent of the frequencyof said waves comprising aplu v rality of thermionic devices eachcomprising an anode, cathode and grid, atuned circuit comprisinginductance and capacity, the inductance of said circuit being relativelylarge with respect to the capacity, connections from said grids toopposite terminals of said inductance, a signal translating instrument,couplings between the same and neeegeee the anode circuits of seioithermionic devices, and e souroe of current of audible frequencyassociated With said thermionic devices, said couplingsproducing equaland 5 opposite effects upon seid signel rrenslsrt ing instrument when nosignal is received and producing thereln when a signal is reof thefrequent:

oeived a, current of frequency independent of said Waves andcorrespending with i; e frequency of said source.

In testimony whereof I have hereunto affixed my signature this 26th dayof November, 1920.

FREDERICK A. KULSTER.

